A so-called pneumatic false-twisting spinning method comprising passing a sliver through an air jetting nozzle to effect false twisting and spinning by swiring air streams has been known from the specifications of U.S. Pat. No. 3,079,746, U.S. Pat. No. 3,978,648, U.S. Patent Application Ser. No. 682,272 and U.S. Pat. application Ser. No. 730,349.
In the pneumatic false-twisting spinning method, false twists imparted to fibers by air jetting nozzles are propagated to a drafting zone, and by such false twists single fibers of the sliver are twisted to form yarns. For improving propagation of false twists and probably for other unknown reasons, it is preferred that all the devices from the drafting zone to the take-out roller through the intermediate spinning zone be arranged substantially in a line. If such layout is adopted, product yarns having a high strength and a good quality can be obtained and occurrence of yarn breakages can be remarkably reduced. It is in the drafting zone and the spinning zone that yarn breakages occur most frequently during the spinning operation, and in the spinning zone, an operator should pick up yarns every time yarn breakage takes place. Accordingly, it is necessary to arrange the spinning zone in such a place that the operation can be inspected most easily and an operator can work with ease without any difficulty.
In case of the conventional knotting device of the type where when yarn breakage takes place, the knotting device is travelled along lines of yarns, there is adopted such an arrangement that the knotting device is travelled in front of the yarn lines. Namely, in this case, the knotting device is travelled in the space between an operator and yarn lines. Accordingly, the operation of the operator is often disturbed by the travel of the knotting device, and the operation space is inevitably narrowed. Moreover, when exchange of bobbins is conducted, if spare sliver bobbins are not present in the vicinity of empty bobbins to be exchanged, this bobbin exchange operation requires time and trouble.